The structural integrity of a vessel hull is an important safety an economical concern. For example, frictional resistance due to buildup on or fouling of the hull by algae, sea grass, barnacles, and the like as a vessel moves through the water can increase the fuel consumption of the vessel. The result is added cost to operate the vessel and increased emissions. Moreover, monitoring of damage to the hull is useful in determining when and where repairs should be made.
A variety of methods are currently employed to lower the chance of bio-fouling and to monitor the structural integrity of the hull. For example, typically, while the ship is dockside and/or during normal unlading conditions, the hull can be periodically inspected manually, such as by scuba divers using various equipment. The cost of such an inspection procedure can be costly. This type of inspection effort may be repeated at a predetermined period of months, such as every ten to twenty months or sooner, particularly if there is suspicion of damage to the vessel hull. To properly inspect the vessel hull, the hull often must first be cleaned. As a complication, however, some jurisdictions have made dockside cleaning illegal due to the release of contaminants into the water, and particularly particles of anti-fouling paint which is toxic, and which has been found to contaminate the water.
Most prior hull cleaning robots suffer from various shortcomings. Typically, robots are connected to a cable and powered and controlled by an on-board power supply and control system and are able to operate only on a stationary vessel. Further, inspection techniques for determining the cleanliness of the hull are inefficient. The monetary cost and intrinsic value of such robots can be high, and therefore, there is a desire to properly secure the robot to avoid damage or loss.